This Part Fits the following kits / parts:

#76983 - アルミ ピニオンギヤ 23Ｔ

#86038 ナイトロ3 2スピードセット オプションギヤ

Available from HPI Racing are a selection of Aluminum Threaded
Pinion Gears for the Nitro 3! This wide range of gears allows Nitro
3 racers with the #86038 Two Speed
Transmission to fine tune the gearing for any size track.